Laser manufacturing has become a critical machining process due to its capability to create complex shapes/structures versus conventional methods. With the advent of ultrashort pulse laser technology, i.e. pulse duration less than 100 fs, more complex and sophisticated machining processes can be realized on a broader array of materials, e.g. large band-gap materials, high reflectivity material or ceramics. However, the present laser manufacturing approach is mainly based on point-scanning the focal point of a laser which will sequentially and inherently makes process slow. In addition, the point-scanning process cannot be expedited by increasing the laser power as the resolution will be compromised with thermal effects, e.g. melting and redeposition. Other methods, e.g. laser projection, trade resolution for throughput. Consequently, ultrashort pulse lasers, though highly capable, are mainly used for prototyping and fundamental research.
Recent research shows that the temporal focusing technique could significantly improve the throughput of freeform microstructure manufacturing in polymer. This technique achieves its 3D sectioning capability by regulating the laser pulse width such that it is minimized only at the focal plane, and unlike conventional point-scanning method, temporal focusing fabrication directly projects the wide-field excitation pattern on the focal plane through a diffraction component and an objective, thus significantly increasing the yield. However, projection through a diffraction component will sacrifice the resolution. And in manufacturing, it is also highly desired that large-area patterns can be simultaneously fabricated on metals via laser, an ability that has not been demonstrated using temporal focusing.